The present invention relates to an optical recording and reproducing device utilizing disks having circular and/or spiral record tracks.
There has been invented and demonstrated an optical recording and reproducing system in which a laser light beam less than 1 .mu.m in diameter is focused on a spinning disk coated with a photosensitive compound, so that data can be recorded in the form of a variable-density track or an irregular surface track at a high data-packing density; for reproduction a reading laser light beam is used. The optical video disks have been well known as a means only for reproducing the data pre-recorded at a higher degree of data-packing density. This technique has been used to record video signals, audio signals and digital signals.